Hypertension and Heart Failure Flashcards
Describe the different grades of hypertension
- Hypertension defined as 140/90 mmHg
- Grade 1: 140-159 / 90-99 mmHg
- Grade 2: 160-179 / 100-109 mmHg
- Grade 3: > 180 / >110 mmHg
List some non-pharmacological management of hypertension
- Patient education
- Maintain normal body weight and BMI
- Reduce salt intake to < 6g/day
- Limit alcohol consumption to < 3units/day for men and < 2 units/day for women
- Engage in regular aerobic physical exercise for > 30 minutes/day
- Consume > 5 portions of fresh fruit/vegetables daily
- Reduce intake of total and saturated fat
- Smoking cessation
List the main classes of antihypertensive drugs
- ACE inhibitors
- Angiotensin receptor blockers
- Calcium channel blockers
- Diuretics
- Alpha and beta blockers
- Direct renin inhibitor
- Centrally acting agents
Describe the mechanism of ACE inhibitors
- Eg. Ramipril, lisinopril
- Competitive inhibitor of angiotensin converting enzyme
- Reduction in formation of angiotensin II
- Arterial vasodilators
- Some venodilation
- Circulating aldosterone is reduced
- Potentiates the action of bradykinin (stops breakdown of bradykinin) - vasodilator
List the main ADRs of ACE inhibitors
- HARD
- Hyperkalaemia - reduced Na reabsorption leading to reduced K secretion
- Angio-oedema - increased circulating fluid
- Renal failure
- Dry cough due to bradykinin
Describe the mechanism of angiotensin receptor blockers
- Eg. Losartan, candesartan
- Bind to angiotensin AT1 receptor
- Inhibit vasoconstriction and aldosterone stimulation caused by angiotensin II
- Increased release of NO - vasodilator
- Inhibit vasoconstriction and aldosterone stimulation caused by angiotensin II
List the main side effects of angiotensin receptor blockers
- Renal failure
- Hyperkalaemia - reduced Na reabsorption leading to reduced K secretion
State the 3 classes of calcium channel blockers
- Dihydropyridines
- Phenylalkylamines
- Benzothiazepines
Describe the use of dihydropyridines
- Eg. Nifedipine, amlodipine
- Main calcium channel blocker used in hypertension
- Baroreflex mediated tachycardia
Describe the main side effects of dihydropyridines
- FOGS
- Flushing, sweating, throbbing headache
- Oedema - ankle swelling
- Gingival hyperplasia - increased size of gums
- Sympathetic nervous system activation - tachycardia and palpitations
Describe the uses of phenylalkylamines
- Eg. Verapamil
- Useful in treating angina and arrhythmia
- Depresses SA node and slows AV conduction
- Impedes calcium transport across the myocardial and vascular smooth muscle cell membrane
- Peripheral vasodilation and a reduction in cardiac preload and myocardial contractility
List the main side effects of phenylalkylamines
- Constipation
- Risk of bradycardia
- Reduce myocardial contractility (negative inotrope) - can worsen heart failure
Describe the uses of benzothiazepines
- Eg. Diltiazem
- Impedes calcium transport across the myocardial and vascular smooth muscle cell membrane
- Prolongs the action potential/effective refractory period - also useful in arrhythmias
- Peripheral vasodilation and a reduction in cardiac preload and myocardial contractility
- Not as effective as amlodipine in treating hypertension but less risk of heart failure - used in angina
- Less cardiac stimulation as side effect
List the main side effects of bezothiazepines
- Risk of bradycardia
- Congestion, cough
- Fever, runny nose
- Less negative inotropic effect than verapamil - can worsen heart failure
State the type of diuretics given as anti-hypertensives and its effect
- Mainly thiazides (bendroflumethiazide, indapamide)
- Reduces sodium reabsorption, thus reducing blood volume
- Also acts as vasodilator to lower total peripheral resistance
- Reduces sodium reabsorption, thus reducing blood volume
- Spironolactone given to secondary hypertension due to hyperaldosteronism
- Acts as angiotensin receptor blocker